Airfloor System Mandan ND

An Airfloor system in Mandan is made up of hundreds of 12-square-inch, igloo-shaped metal forms that are 3.5 inches tall and open on four sides. The metal forms are snapped together to create a hollow floor, which sits on top of the home's subfloor.

Heating From Below

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Compared to the media attention that wind, ethanol and geothermal power garner these days, solar energy seems positively prehistoric. "Didn't they try that years ago?" some ask. "Doesn't it only work if it's sunny out?"

Gary Watrous, an architect based in Louisville, Ky., is defying assumptions by proving, through his Sun-Earth home designs, that even after the sun sets, solar energy can power your home's climate, and for only a fraction of the cost of conventional sources.

Solar Architecture

Watrous designs Sun-Earth Homes with his self-described "solar architecture firm," Watrous Associates Architects P.S.C., where he serves as owner and main architect. The homes, which he designs in all shapes and sizes, employ passive solar technology and "Airfloor" systems to control the residences' most expensive cost outside of the mortgage: heating and cooling. Utilizing passive solar to trap energy and Airfloor technologies to store it cuts utility bills in the homes drastically. "Our goal is that Sun-Earth homes will cost the same as conventional homes to construct, but will save two to three times the amount of energy each month," Watrous says.

The technology can be understood by anyone who opens his or her car door on a chilly (yet sunny) winter day to find the interior surprisingly warm. Sunlight streams in through the car's windows and heats the air, which is trapped inside. The same thing occurs in a typical home: the sun's rays that pass through the windows heat the interior. Sun-Earth Homes go a step further by harnessing the sun's energy.

Passive solar technology does not need a cloudless Arizona sky to work well; even on cloudy days, more sunlight passes through windows than is lost. "Any day the sun shines - even a partially cloudy day - there will be no need for fuel to be burnt in these homes," Watrous says. He's so confident that using passive solar technology will save his customers money that his firm offers a guarantee: no more than $35 a month will be required to heat and cool every 1,000 square feet of their buildings, or the bill's on him.

But obtaining the sunlight is the easy part - storing it is what presents a challenge. Watrous begins by installing "super insulation," or roughly doubling the insulation you'd find in a typical house. "Generally, this cuts heating and cooling bills in half," he explains. Other methods of energy conservation, such as radiant barriers, conscious house placement on a lot and tree shading, help manage the home's energy use. But it is the Airfloor system built into the floor of each Sun-Earth Home that utilizes passive solar energy effectively.

Igloos Under the Floor

An Airfloor system is made up of hundreds of 12-square-inch, igloo-shaped metal forms that are 3.5 inches tall and open on four sides. The metal forms are snapped together to create a hollow floor, which sits on top of the home's subfloor. Concrete is then poured three inches deep over the honeycomb to create a hollow concrete floor, which can then be covered with wood, tile or carpet.

"A hollow concrete floor is necessary to retain solar heat in the floor," Watrous explains. "It has all of the advantages of a conventional forced-air system, like fast heat up and cool down. But it's also an advanced system of storing solar energy in the floor."

So much passive solar energy enters a house on a sunny day that it's a terrible waste to let the energy escape, Watrous points out. "So what do you do? Open windows and dump the heat out that you just collected? Or find a way to store it?"

The Airfloor not only stores solar energy, but also distributes the heat throughout the house. "It's like having a big warm rock in the middle of your house," Watrous says. Fans in the furnace (with the burners off) cycle warm air through the floor, distributing it to all the rooms in the house, much like traditional ductwork would. This process of cycling keeps the floor warm (or cool, depending on the season) long after the sunsets.

The patented Airfloor system was designed 30 years ago in California by an air conditioning and heating engineer named John Leehamus, but it has deeper historical roots. The concept of using hollow concrete floors to help heat and cool spaces originated with the Romans. "Their hypocaust system [literally, "heat from below"] was a series of hollow concrete tiles that they poured concrete over in bathhouses in Rome," Watrous says. "They had bonfires in the basements to create radiant floor systems. The problem was that a crack in a wall or floor would kill them all, because of the gasses. Luckily, the Airfloor system uses fresh air, so that's not a worry," he notes with a laugh.

Also appealing to those who live in the North is the fact that a home with an Airfloor system takes days to cool to uncomfortable temperatures if there is a power outage.

My New Kentucky Home

"We had three goals when building this house," says Klem. "We wanted an energy efficient home; we wanted a home with no exterior maintenance; and we wanted to be able to grow old here. We got the first two; we're working on the third."

The Fisherville House is a 3,500-square-foot residence in Fisherville, Ky., that Watrous designed in the Prairie style reminiscent of Frank Lloyd Wright. It is one of Watrous' favorite designs. "It is very avant garde, but at the same time it has the grace of Prairie style," he says. The house is positioned at 10 degrees east and due south, which allows the sun to "shine in [strongly] during the winter and shallowly in the summer," says Klem.

"We lived in a smaller home before we moved in here. Now we have around 500 to 800 more square feet," she notes, "but our utility bills are half of what they were in our old house. Five years have passed and rates have gone up for electrical services, but we're still sitting at around half of what it used to cost us."

Klem says she couldn't be a happier customer - and she's the exact demographic Watrous most commonly designs for. "Most of my clients are environmentalists concerned about energy efficiency and global warming. They want to be good stewards of the earth but want to save money at the same time." Many of his clients, he adds, are "aging baby boomers" who want to downsize their living space, and simultaneously are looking to lock in low energy rates. "They want to have a house that uses a lot less energy when prices increase in the future, which they surely will do."

Word of Mouth

While the homes are designed to operate especially well in the Midwestern climate, clients come to Watrous' firm from around the country to have a Sun-Earth home designed specifically for them, or to buy a plan. His website ( http://www.sunearth.net ) attracts a great deal of his customers, but so does word of mouth. Klem found out about Watrous from friends who had a house designed by the architect.

Watrous earned his architectural master's degree from Yale University. One of his most influential teachers, Douglas Balcomb, is considered a "godfather" to those interested in renewable energy. His teachings helped inspire Watrous to open his firm in 1985.

Watrous designs Sun-Earth Homes in a variety of sizes and styles, and applies the design philosophy to a wider range of structures as well. For instance, he has used passive solar and Airfloor technologies when designing churches, day car facilities and even a fire station. He also helped design an eco-village of communal living that was intended for construction near downtown Louisville.

Although the community was never built, the idea was incredibly interesting to Watrous. "It's a concept I've always been interested in: everybody would have a small home in the village, maybe smaller than normal because they would share a group building that would have central facilities, like a library, a tool workshop, a swimming pool and more. The residents would have at least one dinner a week together, if not seven. There'd be a real sense of a community."

Watrous' clients invest in energy savings up front to build their Sun-Earth homes or buildings, but the payoff over the long term is huge. Even those who care nothing about the environment can't deny the savings that come from the investment in his designs.

"Every week there's at least one article about global warming," he says. "It's been on people's minds." Passive solar energy may heat your car for free, but paying for an Airfloor system now clearly ensures that despite rising temperatures, you won't have to pay later.

There are plenty of choices in Mandan when it comes to replacing the air filters in your home comfort system. A visit to a home center may produce a half dozen or more different filters that could be used, ranging in price from 49 cents to $15. Their effectiveness varies widely, too. So which is the right one? The primary reason for a filter in your furnace is to protect the equipment.